German Patent Application No. DE 44 26 020 describes a method, in which the operativeness of a catalytic converter, that is situated in the exhaust gas region of an internal combustion engine, is monitored. The monitoring is performed with the aid of the temperature increase generated by an exothermic reaction of the exhaust gases in the catalytic converter. Two temperature signals are ascertained, the first temperature signal being based on a measurement of the temperature downstream from the catalytic converter, and the second temperature signal being calculated with the aid of a model.
The present invention is based on the object of providing a method for monitoring a component situated in the exhaust gas region of an internal combustion engine, which makes possible making a statement concerning a change in the component.